Solar quote calculator
Check a rooftop system before you quote it: is the DC/AC ratio within the limit, what the customer pays with tax, what subsidy they can claim, and how long it takes to pay back.
The system
Starting values are examples. Replace each one with your own.
Before tax.
Most installers allow 10 to 30% on-grid.
Subsidy
Savings assumptions
Depends on location. 1,300 to 1,600 is common in India.
The estimate
- DC-to-AC ratio
- 1.1 within limit
- System price with tax
- ₹2,15,622
- Subsidy the customer can claim
- ₹78,000
- Cost to the customer after subsidy
- ₹1,37,622
- Yearly generation and saving
- 4,620 kWh · ₹32,340
- Simple payback
- 4.3 years
How this is worked out
- DC-to-AC ratio = panel kWp / inverter kW, checked against your oversize limit.
- Price = kWp × price per kWp, plus tax (₹17,622 here): 5% on 70% of the value and 18% on 30%.
- Subsidy = central amount by kW slab, up to the cap, plus the state top-up. It is shown separately because in many schemes it is paid to the customer after installation.
- Yearly generation = kWp × generation per kWp. Saving = generation × tariff.
- Payback = cost after subsidy / yearly saving. It ignores maintenance and tariff changes.
Every number is your own input. None of it is a claim by AIMS.
Quoting solar every day? AIMS IQ applies your sizing limits, subsidy slabs and tax on every quote. See solar quotations.
Questions
What DC/AC ratio is allowed on an on-grid system?
It depends on the inverter maker and the local utility. Many allow the panel (DC) capacity to exceed the inverter (AC) rating by 20 to 40 percent. Enter your own limit; the calculator flags any system above it.
How is GST worked out on a solar system in India?
A common practice treats 70 percent of the contract value as goods at 5 percent GST and 30 percent as services at 18 percent. Tick India GST to use that split, or untick it and enter one tax rate for your country.
Which subsidy amounts does the calculator use?
The defaults are the central amounts under India’s PM Surya Ghar scheme for homes: 30,000 rupees per kW for the first 2 kW, 18,000 for the third, capped at 78,000. Every amount is editable, and you can add a state top-up or turn the subsidy off.
Is the payback figure exact?
No. It divides the net cost by the first-year saving and ignores panel degradation, tariff changes and maintenance. Use it to compare options, not as a promise to a customer.
Guides for solar installers
- DC-to-AC ratio: setting sizing limits on quotes
What the DC-to-AC ratio is, why installers oversize panels against the inverter, and how to put a limit on every quote so no rep goes too far.
- Net-metering paperwork: fill it once from the quote
Why net-metering and subsidy paperwork slows solar jobs down, and how to fill every form from the quote instead of retyping it.
- How to build a solar quote that doesn't miss items
The items solar quotes most often miss, why they get missed, and how to make every quote complete without relying on memory.
- How to show solar subsidy on a customer quote
Show solar subsidy clearly on a quote, keep it separate from your price, and stop errors when subsidy slabs or amounts change.